Silencer



Dec. 18, 1928. 1,695,435

H. P. MAXIM SILENCER Filed Sept.v 1925 2 Sheets-Sheet 2 Z9 r: 222;. iii

INVENTOR.

dw M

ATTORNEYS.

Patented Dec. 18, 1928.,

ENT OFFICE.

HIRAM PERCY MAXIM, OF HARTFORD, CONNECTICUT, 'ASSIGNOR TO THE MAXIM SILENCELR COMPANY,

OF HARTFORD, N ECTICIJ'T.

CONNECTICUT, A CORPORATION OF CON- SIILENCER.

Application filed September a," 1925. sw rm. 55,042.

This invention relates to silencers for ap- The header 4.- has attached thereto the si- 56 v plication to the exhausts of oil, gas, air orsteam engines and intakes of compressors, blowers and like mechanisms. 1

One of the principal objects of the invention is to provide a'silencer of the proper design for quieting the noise from such exhausts or intakes without appreciably obstructing the free flow of the gases therethrough. Coupled with this object is one of providin a silencer .of such improved and simplifie construction as will facilitate the manufacture of the same in quantity and in a wide variety of sizes at low manufacturing costs.

The attainment of the above and other advantages will be readily appreciated from the more detailed description of the invention which follows taken in connection with the accompanying drawings which show a preferred em odiment of the invention.

Referring briefly to said drawings Fig. 1 is a view of a. silencer showing the exterior shell in section and the silencing unit thereof in elevation;

Fig. 2 is a transverse section of the silencer taken along line 2-2 of Fig.1; and

Fig. 3 is a view of a slightly modified form of silencer shown in longitudinal section.

Referring" more particularly to Figs. 1 and 2 of the drawings, 1 indicates the exterior shell or casing of the silencer which may be in the usual cylindrical form and is preferably of sheet metal. The ends of the shell are provided with suitable flanges 2 by which headers 3 and 4 are secured to the shell through bolts 5. The header 3 is formed with a center opening 6 which may be termed the inlet of the silencer. The outer side of the header 3 adjacent the inlet 0 ening is provided with a suitable flange 7 or a ipe connection to the device to be silence and on the inside of said header 3 a flange 8 is pref-- erably provided to serve as a dam in preventing water of condensation or other waste material draining back through the inlet when the silencer is used in vertical osition. An additional opening 9, adapted to e closed by plug 10, may also be provided in the header 3, as shown, and a similar opening 11 for closure b plug 12 may be provided in the lower side 0 the shell 1, said latter'openings serving when desired as a drain or inlet for water.

lencing unit 15 in spaced relation from the header 3 to form an expansion chamber 21 within the shell, and said header 4-is prov 'vided with a center opening 13 therethrough surrounded'by suitable flange 14 for a pi e connection and may be termed the out at opening for the silencer. It will be understood, however, that such silencers are frequently applied to intake ports of air compressors and the like as Well as to the exhaust ports of engines. In any event, the silencer is usually attached with the expa.n sion chamber end adjacent the unit to be silenced in which case the gas flow may be in either direction through said inlet and outlet openings according to circumstances.

The header 4 of the shell 1 also serves as a header or end closure for the silencin unit 15 which will now be more particular y described. This silencing unit is substantially in the form of a sheet scroll-wound spirally from a core chamber at its axis outwardly to its periphery, as shown clearly in Fi 2. The wall of this scroll is preferabl ofs eet metal to reduce weight and is ma e up into sections 15' to both cheapen the cost of manufacture and to facilitate assembly of the silencer parts. As shown, the several sec tions of sheet metal making up the scroll are, each curved to form part of the continuous convolutions of the scroll and the ends of adjacent sections are overlapped upon one'another at joints 16. In certain small sizes of the silencer, the sections of the scroll may be continuous for almost an entire convolution and therefore rovide joints 360 degrees apart but in large sizes of silencer and scroll it is desirable to employ sections of smaller angular extent for ease in-man'ufacture and handling and, as shown in-Fig. 2, provide joints 180 degrees apart. Obviously, said oints may be made at angular distances apart even less than 180 degrees if desired. The over lapped joints 16 between ad'acent sections extend'longitudinally and pre erably parallel to the axis of said scroll and are securelyfastened b means of radially disposed tiebolts 17. hese tie bolts 17 also carry spacing collars or thimbles 18 between the spaced wall of the scroll for holding same in this spirally spaced relation. a 1y disposed bolts 19 may likewise be pro- Additional radifastening bolts 21 having screw threaded ends 22 may be riveted or welded to an ularly spaced portions of the scroll sheet with their screw threaded ends 22 extended through the headers for receiving fastening nuts. The header 20..is somewhat smaller in diameter than header 4 and is referably flanged at its periphery to over ap the sides of the scroll and make a close fit. Spaced at angular distances around the periphery of said header 20 and projectln radially therefrom are secured legs 23 which serve to support and space the inner end 01! said silencing unit 15 from the inside of shell 1. The legs 23 merely rest against the inner side of shell 1 so that the silencer unit as a whole may expand and contract independently of said shell 1. It will be observed also that the silencer unit 15 being secured to the header 1 is removable therewith as a unit from the shell 1. This arran ement contributes to the easy assembly of t e parts and removal of the same for cleaning.

From the fore oing description of the con struction, it\ W1 be apparent that exhaust gases and sound waves issuing from an explosive engine will enter throu h inlet 6 into the expansion chamber 21. T he gases will then flow around the periphery of said silencing unit 15 and find entrance to the scroll at the opening 24 upon a lateral side of said silencing unit (see Fi 2%). They will then take a course through t e spiral assageway of the scroll until they reach t e opening 25 leading into the central core chamber 26 of said silencing unit. The core chamber 26 is in line with the outlet 13 through header 4 through which the gases are finally discharged. During their course through the silencer, successive discharges of gas into the ex ansion chamber27 are smoothed out for a su stantially even flow through the spiral silencing unit and are thereby delivered to the exit in such a continuous manner as to produce no sudden blows upon the air for generating sound. Furthermore, the delivery of the discharge gases throu h the silencer is not substantially checked 3y interi'ering bszhes but on the contrary the course of the same is one or gradual rather than abrupt change so that little or no impedance 3': back pressure is crea' ed. The sound. waves from the explosive noise originating at the exhaust valves of the engine likewise entering the silencer are, by re ated reflections during their course throng the spiral pas sage-way, effectively dissipated in energy so as to be hardly perceptible when issuing from the outlet.

Referring to the modification shown in Fig. 3, the sheet scroll 28 is made up in sections in precisel the same manner as previously described and as shown in Fig. 2. The sections are locked together at their joints and the spiral walls of the scroll are spaced by means of the radial tie bolts 29 and spacing collars 30 similar to 17 and 18. In this form of silencer which is desi ncd for a smaller and less expensive instali ation, the expansion chamber and exterior shell or casing are omitted. The headers for the scroll comprise disk plates 31 and 32, thelatter of which may be suitably formed with a central opening and tapered throat 33 for connection to a pipe 36 and serving as the inlet to the silencer. A single tie bolt 34 is axially disposed and extended through the header 31 and a bracket 35 formed across the throat 33 for holding the headers 31 and 32 to ether and against the interposed scroll. n this form of silencer, the gas and sound waves entering by the pipe 35 take a course spirally through the scroll to the periphery there-- of and eventually find an. out et at the end of the spiral passageway at one side of the scroll, similar to the opening indicated at 24 in Fig. 2. This form of silencer is more particularly adapted for installation at the end of an exhaust or intake pipe.

The design of scroll construction in both forms of sllencer shown, easily lends itself to the employment of sheet metal so desirable in instal ations where objectionable weight is a factor to be considered. Moreover, the employment of sectional parts and assembly of the same in the manner shown contributes to the production of silencers at low cost without lessening efiicien cy or durability over heavier and more expensive constructions.

It will be understood that the embodiment of the invention as herein disclosed is capable of wide differentiation in equivalent forms and changes of detail and accordingly the invention is not intended to be limited by the requirements for a specific description as given above, but on the contrary is to be determined by a liberal interpretation of the appended c aims.

Iclaim:

1. A silencer comprising a spiral sheet scroll interposed between header plates to form a continuous closed uninterrupted spiral passage from an axial. hamber to a lateral peripheral. opening, the wall of said scroll being made up of sections each form ing part or the continuous convolutions of said scroll, the joints of the adjacent sections in each successive convolution of said scroll bein located in radial alignment, and means for fastening said sections together at said oints.

2. A silencer comprising a spiral sheet scroll interposed between header plates to form a continuous closed uninterrupted spiral passage from an axial chamber to a lateral peripheral opening, the cross-sectional area of said passage being of substantially greater width axially of scroll than radially of said scroll, the wall of said scroll being made up of sections each forming part of the continuous convolutions of said scroll, the joints of the adjacent sections in each successive convolution of said scroll being located in radial alignment, and means for fastening said sections together at said joints.

3. A silencer comprising, a spiral sheet 'scroll interposed between header plates to form a continuous closed uninterrupted spiral passage from an axial chamber to a lateral peripheral opening,'the wall of said scroll being made up of sections each forming part of the continuous convolutions of said scroll, the joints of the adjacent sections in each successiveconvolution of said scroll being located in alignment, and tie bolts extending through said aligned joints for fastening said sections together.

4. A silencer comprising a spiral sheet scroll interposed between header plates to form a continuous closed uninterrupted spi-.'

ral passage from an axial chamber to a lateral peripheral opening, the wall of said scroll being made up of sections each forming part of the continuous convolutions-of said scroll, the joints of the adjacent sections in each successive convolution of said scroll bescroll being made up o sections each form-' ing part ofthe, continuous convolutions of said scroll, the joints of the adjacent sections in each successive convolution of said scroll belng located in radial alignment, and nullally disposed tie bolts each extending Q through several of said joints for fastening said sections together, said tie bolts having.

associated therewith portions for spacingthe wall-of said scroll. I

6. 'A-silencer comprising a spiral sheet scroll interposed between header plates to form a continuous closed uninterrupted spi v spiral sheet ral passage from an axial chamber to a let eral peripheral opening, the wall of said scroll being made up of sections, each form ing part of the continuous convolutions of said scroll, the joints of the adjacent sections in each successive convolution of said scroll being in radial alignment, radially disposed tie bolts, each extending through several of said joints for fastening said sections together, and an exterior shell within which said scroll is mounted and having anexpansion chamber atone side of said scroll.

In testimony whereof I have afiixed my signature.

HIRAM PERCY MAXIM. 

